Honda ATV Innovation

From its unassuming beginnings in 1948, Honda has been
defined by
creative thinking. Everything that wears a Honda logo comes
from a
heritage so deeply rooted in innovation that standing still is the
same as going backward. Which is why--from the first 1970
ATC90 to
the 2003 FourTrax® Rincon™--more advancements in ATV
technology
have come from Honda than anyone else.

Honda ATVs have always been about smart solutions to
tough
problems. That sort of fresh thinking goes deeper than flashy
technology. It transcends any simplistic bigger-equals-better
mentality. Much deeper. Honda's ATV engineering is based on
the
premise that the truly great ideas are the ones that stand up to a
full day's work. That's why Honda ATV engineers tackle the
challenges
of research and development firsthand. They ask questions.
They
understand what customers expect a product to do, perhaps
better than
the customers themselves. Staying ahead of the curve with ATV
engineering that's as functional as it is innovative isn't easy. It's
just the Honda Way. What follows is a compendium of landmark
Honda
innovations that have shaped the development of the All-Terrain
Vehicle.

Automotive-style Automatic Transmission

A first in the ATV world, the Rincon incorporates a true
automotive-style automatic transmission to route power from the
engine through a hydraulic torque converter to drive to three
forward
gears and reverse. An electronic control unit (ECU) takes data
regarding throttle opening, vehicle speed, engine speed, gear
selector position, brake application and engine oil temperature
to
determine the optimum gear selection. And because the Honda
automatic
transmission shifts electronically, there are no unsightly and
trouble-prone vacuum lines. Plus, the system provides true
engine
braking, unlike the belt-drive systems used on other brands of
ATVs.
In addition, the Honda automatic transmission is fully sealed
and
impervious to external contamination. Since the transmission
uses
multi-filtered engine oil as hydraulic fluid, this design simplifies
maintenance and ensures an adequate fluid supply under all
operating
conditions.

Independent Rear Suspension

As another notable Honda first, the Rincon features an
independent
rear suspension with lightweight forged aluminum components
to
provide plenty of sophisticated, well-controlled wheel travel. This
double-wishbone design incorporates forged aluminum
knuckles and
upper/lower A-arms that are not only strong but also yield a
significant savings in unsprung weight. The rear knuckle pivots
feature lightweight metal bushings in place of conventional ball
joints and radius arms, thereby eliminating toe-in as the rear
suspension travels through its stroke. This elegantly simple
design
maintains rear wheel alignment and further reduces unsprung
weight,
contributing to the Rincon's responsive handling. Also,
lightweight
single-tube gas-charged rear shocks and a stabilizer bar deliver
plush, well-controlled damping through the Rincon's exceptional
8.0
inches of rear wheel travel. As an added bonus, the lack of a rear
final drive case adds to the Rincon's laudable ground clearance
for
even better maneuverability.

Longitudinal Engine/Driveline

Though Honda's circle of engineering is comprised of
interdependent components, ingenuity often radiates outward
from a
single bit of bright-think that makes a host of seemingly
unrelated
advancements possible.

Perhaps the most illustrative example of this is the powerful
efficiency of Honda's longitudinal engine and driveline layout
introduced on the 1995 Foreman® 400, and currently found in
the
Foreman 450, Recon®, Rancher™, Rubicon™ and Rincon
models.
It's an optimal system sending power to the wheels in the most
efficient manner: straight lines. The longitudinal layout has many
advantages: a lower center of gravity, low seat height, increased
ground clearance, lighter weight and fewer moving parts than
traditional engine driveline systems.

First, the big picture. By aligning its crankshaft with the
vehicle's direction of travel, the longitudinal layout creates a
lighter, simpler, elegantly efficient way of sending power to an
ATV's drive wheels. This simplicity may be best seen in the
driveline: Using 45 percent fewer parts, the Foreman 400 4x4
transmission, for example, weighs 41 percent less than the
more
conventional design used in Honda's legendary FourTrax 300
4x4, and
delivers power to the wheels with 5 percent more efficiency.

Honda's longitudinal engine also rides low enough in the
frame to
optimize ground clearance and define a low seat height, a
difficult
accomplishment in ATV design. Ordinarily, increasing ground
clearance
to avoid hang-ups such as rocks and stumps would raise the
entire
vehicle. But raising the entire vehicle also raises its center of
mass. That compromises handling, especially when traversing
inclines,
an unacceptable situation to Honda engineers.

The solution is Honda's shorter, overhead valve (OHV)
engine
design. Using pushrod valve actuation, this OHV design carries
its
camshaft down in the crankcase rather than up in the cylinder
head to
reduce engine height. The room that would have been taken up
by an
overhead cam is put to better use, lowering center of mass,
lowering
seat height and increasing ground clearance. A counter-rotating
balance shaft makes the rubber-mounted engine smoother,
smooth enough
to allow the use of a lighter frame than would otherwise be
necessary.

Because Honda also wanted to maintain the power
characteristics of
an overhead-cam engine, namely the ability to rev higher than
typical
pushrod engines. Traditional steel pushrods would not work so
lighter
pushrods were necessary. Honda engineers set their sights on
aluminum
to create a lighter, quieter, higher-revving valve train. Aluminum
pushrods expand at the same rate of aluminum cylinder and
cylinder
head, making for more consistent tappet clearance and a quieter
engine than with stainless steel pushrods.

However, aluminum can wear faster and bend more easily
than steel.
A conventional welded steel cap on an aluminum pushrod
created a
brittle joint. Honda's solution was to develop a new aluminum
alloy
pushrod material. Using a unique pushrod end shape, Honda
engineers
came up with a revolutionary design by attaching a steel ball to
the
end of this alloy pushrod. The results? Two tiny steel bearings
and
spark of electricity cleared the way for the most extraordinary,
versatile ATV design on earth. And the bright thinking in Honda
ATVs
goes on from there.

Torque-sensing Differential

The Rancher, Rubicon and Rincon 4x4s use a clutchless
front
differential system that automatically sends power to whichever
front
wheel has the most grip. By virtually eliminating torque steer, the
new system drastically reduces the effort necessary to initiate a
turn.

Electric Shift Program™ (ESP™)

Combining the control of a manual gearbox with the
convenience of
an automatic transmission, the ESP system lets riders shift up
or
down with the push of a button while an electric motor
disengages the
clutch, shifts the gearbox and re-engages the clutch. An onboard
electronic control unit controls the speed of each shift perfectly
after considering engine rpm and countershaft speed, as well as
shift
drum and shift spindle angles.

To maintain a smooth ride, ESP won't let the gearbox go into
first
or reverse at engine speeds above 3000 rpm. To ensure
adequate
control on hills, ESP electronics won't approve a shift to neutral
at
speeds greater than 2 mph.

Hondamatic™ Transmission

One of the most ingenious drive systems on wheels, the
Hondamatic
transmission introduced on the 2001 Rubicon creates a
compact, quiet,
maintenance-free package capable of transmitting engine power
with up
to 98 percent operating efficiency. Mounted parallel to the
crankshaft, the Hondamatic system's engine-driven hydraulic
pump
drives a variable-capacity hydraulic motor, producing
continuously
variable torque output with true engine braking. An ingenious set
of
pump and motor pistons work with a motor-side swash plate to
continuously change motor-side hydraulic capacity. The result is
a
smooth, seamless flow of power, perfectly matched to operating
conditions. A dash-mounted knob selects either D1 for
maximum
performance or D2 for maximum torque. A third position puts the
Hondamatic in Honda's exclusive ESP mode, allowing the rider
to
"shift" via two buttons on the Rubicon's left handlebar.

Radial ATV Tires (Sport ATVs)

An industry first on the 1988 FourTrax 250R and currently
offered
on the TRX400EX. True radial design allows a tread pattern with
bigger knobs that get a better grip on the dirt for improved
straight-line acceleration and cornering traction.

Snorkel Air Intake

To keep dirt, water, sand, mud and other indigestibles out of
the
engine's inlet tract, all Honda ATVs route incoming atmosphere
to the
reusable air filter via free-flowing ducting.

Vacuum-piston Carburetor

Work or play, mixing an ATV's air and fuel accurately and
efficiently at all speeds is extremely tough duty. So Honda started
using vacuum-piston carburetors on the FourTrax 300 series in
1988.
The carburetor's vacuum-controlled piston equalizes venturi
vacuum
for smooth acceleration under different conditions. An auxiliary
starter pump on the carburetor body injects extra fuel into the
carburetor to ease starting under sub-zero conditions.

Electrically Heated Carburetor

The ATV-mounted carburetor integral electric heater system
improves driveability and ensures smooth operation in cold
conditions. This feature is found on the Rincon, Foreman ES/S
and the
Rancher series.

Rear Disc Brake

The Rincon comes equipped with Honda's first rear disc ATV
brake.
Located upstream of the differential, this configuration reduces
unsprung weight, and increases ground clearance and wheel
travel. The
Rincon's rear brake also uses a Collet-type caliper--a first on an
ATV--for improved maintenance.

Shaft Drive

Fully sealed shaft drive systems on Honda multi-purpose
models
deliver power to the wheels with maximum efficiency and
minimum
maintenance.

Starting

Hot or cold. Wet or dry. Honda engineers have put untold
hours of
development into exactly what it takes to start an ATV engine
thousands of times under the most demanding conditions so
you never
have to worry about it.

Eccentric Axle Adjusters

O-ring chain-drive systems on Honda's sport ATV models
carry the
rear axle in an eccentric mounting system that is rotated to
maintain
proper tension and perfect rear wheel alignment.

Sealed, Easy-access Maintenance-free Batteries

The sealed design of Honda's ATV batteries give owners
one less
thing to worry about, and they're easy to get at when it's time for a
new one.